Thin film forming apparatus having a gas flow settling device

Abstract

An apparatus for forming a thin film on a substrate by bringing a first gas and a second gas into reaction with each other in a reaction chamber near the surface of the substrate in the reaction chamber. The apparatus has a plasma generating chamber disposed adjacent to the reaction chamber for generating a plasma of the first gas in a predetermined direction. A first gas inlet is provided at the boundary between the plasma generating chamber and the reaction chamber and formed to extend in the predetermined direction, while a second gas inlet is provided in the vicinity of the first gas inlet and extended in the predetermined direction. The apparatus further has a first gas supplying device for introducing the first gas into the plasma generating chamber and for introducing the first gas activated by a plasma in the plasma generating chamber into the reaction chamber through the first gas inlet, and second gas supplying device for supplying the second gas into the reaction chamber through the second gas inlet. A first flow settling device having plates disposed transverse to the flow of the first gas is positioned between the first gas inlet and plasma chamber. A second flow settling device may be located between the second gas supplying device and second gas inlet.

What is claimed is: 
     
       1. An apparatus for forming a thin film on a substrate by reacting first and second gases comprising: a vessel enclosing a reaction chamber;   substrate holding means for holding a substrate in said reaction chamber;   plasma generating means including a waveguide for transmitting microwave energy toward said reaction chamber, said waveguide including two substantially planar, generally parallel, electrically conducting walls that are elongated in a first direction transverse to the direction of propagation of microwaves in said waveguide, and an elongated dielectric window generally parallel to and extending in one of said walls in the first direction for transmitting microwave energy from the waveguide to a first gas inlet means;   first gas inlet means disposed between said plasma generating means and said reaction chamber including a plasma chamber extending in the first direction for receiving microwave energy transmitted through the dielectric window to establish and maintain a plasma in the first gas in said plasma chamber, a first gas inlet for supplying the first gas to said plasma chamber, first flow settling means disposed between said first gas inlet and said plasma chamber for settling flow of the first gas into the plasma chamber including plates disposed transverse to the flow of the first gas for establishing a tortuous flow path for the first gas, and including an elongated opening extending in the first direction for flow of the first gas from said plasma chamber into said reaction chamber; and   second gas inlet means including an outlet extending in the first direction in communication with said reaction chamber for supplying the second gas to said reaction chamber, said outlet being disposed proximate the opening of said first gas inlet means.   
     
     
       2. The apparatus of claim 1 wherein said plasma generating means includes: a microwave resonator disposed in said waveguide and extending in the first direction   
     
     
       3. The apparatus according to claim 1, comprising evacuation means for evacuating gases from said reaction chamber. 
     
     
       4. The apparatus according to claim 1 wherein said second gas inlet means comprises a second gas inlet for admitting the second gas and second flow settling means disposed between said second gas inlet and said outlet for settling the flow of the second gas into said reaction chamber. 
     
     
       5. The apparatus according to claim 1, comprising heating means for heating substrate held by said substrate holding means. 
     
     
       6. The apparatus according to claim 1, comprising driving means within said reaction chamber for moving said substrate holding means. 
     
     
       7. The apparatus according to claim 6 wherein said driving means includes means for moving said substrate holding means in said first direction. 
     
     
       8. The apparatus according to claim 1, comprising power supply means for charging a substrate on said substrate holding means to a preselected electrical potential level. 
     
     
       9. The apparatus according to claim 1 wherein said outlet comprises a plurality of uniformly spaced holes extending in the first direction. 
     
     
       10. The apparatus according to claim 1 including gauze disposed in the opening in said first gas inlet means between said plasma chamber and said reaction chamber. 
     
     
       11. The apparatus according to claim 4 wherein said second flow settling means comprises plates disposed transverse to the flow of the second gas for establishing a tortuous flow path for the second gas.